Semiconductor device and a method of forming the semiconductor device

ABSTRACT

According to various embodiments, a device may include: a semiconductor region; a metallization layer disposed over the semiconductor region; and a self-organizing barrier layer disposed between the metallization layer and the semiconductor region, wherein the self-organizing barrier layer comprises a first metal configured to be self-segregating from the metallization layer.

RELATED APPLICATION(S)

This application is a divisional of U.S. patent application Ser. No.14/953,502, filed Nov. 30, 2015, entitled, “A SELF-ORGANIZING BARRIERLAYER DISPOSED BETWEEN A METALLIZATION LAYER AND A SEMICONDUCTORREGION”, the contents of which are hereby incorporated by reference intheir entirety.

TECHNICAL FIELD

Various embodiments relate generally to a semiconductor device and amethod of forming the semiconductor device.

BACKGROUND

In general, a semiconductor device may be processed in semiconductortechnology, on and/or in a substrate (also referred to as a wafer or acarrier). The substrate may include a plurality of semiconductordevices, e.g. chips, which are processed or mounted in correspondingregions of the substrate. For fabricating such semiconductor devices,certain layers and layer stacks are formed, e.g. electricalinterconnections, barriers, and active regions.

Conventionally, certain layer combinations and/or material combinationsrequire a diffusion separation from each other, e.g. if they tend toreact with each other. The diffusion separation may be provided by abarrier layer. However, during processing, higher temperatures mayincrease the reactivity and/or mobility of the atoms such that thebarrier layer usually requires a high integrity to prevent diffusionbetween the respective layers. Defects in the barrier layer, which mayarise during the processing, may impair the integrity of the barrierlayer and may allow interdiffusion through the barrier layer, which maydeteriorate the functionality of the layers, e.g. their capability forproviding low resistance electrical connections, or may destroy thesemiconductor device. By way of example, during forming the barrierlayer, surface contaminations may induce holes in the barrier layer,illustratively acting as an interdiffusion gate. Further, a certaindefect density of the barrier layers may decrease the reliability of thebarrier layer with increasing interdiffusion area between the layers. Byway of example, increasing the interface area between a contact pad andthe active area may result in an increase of the failure rate of theproduced semiconductor devices.

During processing of the semiconductor device and/or during reliabilitytesting of the semiconductor device, a high temperature may be appliedto the semiconductor device, e.g. greater than about 200° C., e.g.greater than about 400° C. This may increase a diffusion activity ofmaterial in the semiconductor device increasing a risk of destroying thesemiconductor device during processing or testing.

Conventionally, the reliability of the barrier layer may be increased byincreasing the number of barrier layers, e.g. by forming a barriermultilayer. Barrier multilayers require a higher effort, more processtime, and additional material, which may increase production costs.

The reliability of a barrier multilayer may also decrease withincreasing interdiffusion area. Further, defects arising from surfacecontaminations may extend through all layers of the barrier multilayersand, therefore, may not be reduced by increasing the number of barrierlayers.

SUMMARY

According to various embodiments, a device may include: a semiconductorregion; a metallization layer disposed over the semiconductor region;and a self-organizing barrier layer disposed between the metallizationlayer and the semiconductor region, wherein the self-organizing barrierlayer includes a first metal configured to be self-segregating from themetallization layer.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. The drawings are not necessarilyto scale, emphasis instead generally being placed upon illustrating theprinciples of the invention. In the following description, variousembodiments of the invention are described with reference to thefollowing drawings, in which:

FIGS. 1A and 1B respectively show a semiconductor device according tovarious embodiments, in a method according to various embodiments in aschematic cross sectional view or side view;

FIGS. 2A and 2B respectively show a semiconductor device according tovarious embodiments, in a method according to various embodiments in aschematic cross sectional view or side view;

FIGS. 3A and 3B respectively show a semiconductor device according tovarious embodiments, in a method according to various embodiments in aschematic cross sectional view or side view;

FIGS. 4A and 4B respectively show a schematic diagram;

FIGS. 5A and 5B respectively show a schematic diagram;

FIGS. 6A and 6B respectively show a schematic diagram;

FIGS. 7A and 7B respectively show a schematic diagram;

FIGS. 8A and 8B respectively show a schematic diagram;

FIGS. 9A and 9B respectively show a schematic diagram;

FIGS. 10A and 10B respectively show a schematic diagram;

FIG. 11 shows a schematic diagram;

FIG. 12 shows a semiconductor device according to various embodiments,in a method according to various embodiments in a schematic crosssectional view or side view;

FIG. 13 shows a semiconductor device according to various embodiments,in a method according to various embodiments in a schematic crosssectional view or side view;

FIG. 14 shows a semiconductor device according to various embodiments,in a method according to various embodiments in a schematic crosssectional view or side view;

FIG. 15 shows a method according to various embodiments in a schematicflow diagram;

FIG. 16 shows a method according to various embodiments in a schematicflow diagram;

FIGS. 17A and 17B respectively show a semiconductor device according tovarious embodiments, in a method according to various embodiments in aschematic cross sectional view or side view; and

FIGS. 18A and 18B respectively show a semiconductor device according tovarious embodiments, in a method according to various embodiments in aschematic cross sectional view or side view.

DESCRIPTION

The following detailed description refers to the accompanying drawingsthat show, by way of illustration, specific details and embodiments inwhich the invention may be practiced.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration”. Any embodiment or design described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments or designs.

The word “over” used with regards to a deposited material formed “over”a side or surface, may be used herein to mean that the depositedmaterial may be formed “directly on”, e.g. in direct contact with, theimplied side or surface. The word “over” used with regards to adeposited material formed “over” a side or surface, may be used hereinto mean that the deposited material may be formed “indirectly on” theimplied side or surface with one or more additional layers beingarranged between the implied side or surface and the deposited material.

The term “lateral” used with regards to the “lateral” extension of astructure (or of a substrate, a wafer, or a carrier) or “laterally” nextto, may be used herein to mean an extension or a positional relationshipalong a surface of a substrate, a wafer, or a carrier. That means that asurface of a substrate (e.g. a surface of a carrier, or a surface of awafer) may serve as reference, commonly referred to as the mainprocessing surface of the substrate (or the main processing surface ofthe carrier or wafer). Further, the term “width” used with regards to a“width” of a structure (or of a structure element) may be used herein tomean the lateral extension of a structure. Further, the term “height”used with regards to a height of a structure (or of a structureelement), may be used herein to mean an extension of a structure along adirection perpendicular to the surface of a substrate (e.g.perpendicular to the main processing surface of a substrate). The term“thickness” used with regards to a “thickness” of a layer may be usedherein to mean the spatial extension of the layer perpendicular to thesurface of the support (the material) on which the layer is deposited.If the surface of the support is parallel to the surface of thesubstrate (e.g. to the main processing surface) the “thickness” of thelayer deposited on the support may be the same as the height of thelayer. Further, a “vertical” structure may be referred to as a structureextending in a direction perpendicular to the lateral direction (e.g.perpendicular to the main processing surface of a substrate) and a“vertical” extension may be referred to as an extension along adirection perpendicular to the lateral direction (e.g. an extensionperpendicular to the main processing surface of a substrate).

According to various embodiments, the semiconductor device may includeone or more integrated circuit structures (also referred to assemiconductor chip, IC, chip, or microchip) which are formed duringsemiconductor device fabrication (in other words, in a method forforming the semiconductor device). An integrated circuit structure maybe processed at least partially at least one of over or in a substratein corresponding regions of the substrate (also referred to as activechip regions) utilizing various semiconductor processing technologies.An integrated circuit structure may include one or more (e.g. aplurality of) semiconductor circuit elements, such among others may beat least one of transistors, resistors, capacitors, which areelectrically interconnected and configured to perform operations, e.g.at least one of computing operations, switching operations, rectifieroperations, or storage operations, in the completely processedintegrated circuit structure, e.g. in power electronics. In furthersemiconductor device fabrication a plurality of semiconductor devicesmay be singulated from the substrate (also referred to as a wafer or acarrier) after the semiconductor device processing by wafer-dicing toprovide a plurality of singulated semiconductor devices (also referredto as semiconductor chips) from the plurality of semiconductor devices.Further, a final stage of semiconductor device fabrication may includepackaging (also referred to as assembly, encapsulation, or seal) ofsingulated semiconductor devices, wherein a singulated semiconductordevice may be encased, e.g. into a supporting material (also referred toas molding material or encapsulation material) to prevent physicaldamage and/or corrosion of the semiconductor device. The supportingmaterial encases the semiconductor device (illustratively, forms apackage or mold) and may optionally support the electrical contactsand/or a lead frame to connect the semiconductor device to a peripheraldevice, e.g. to a circuit board.

According to various embodiments, during semiconductor devicefabrication, various material types may be processed to form at leastone of: an integrated circuit structure, a semiconductor circuitelement, a contact pad, an electrical interconnection, such among othermay be electrically insulating materials, electrically semiconductingmaterials (also referred to as semiconductor material) or electricallyconductive materials (also referred to as electrically conductingmaterials).

According to various embodiments, a substrate (also referred to ascarrier or wafer) may include or be formed from at least onesemiconductor material of various types, including a group IVsemiconductor (e.g. silicon (Si) or germanium (Ge)), a group III-Vsemiconductor (e.g. gallium arsenide), or other semiconductor types,including group III semiconductors, group V semiconductors or polymers,for example. In various embodiments, the substrate is made of silicon(doped or undoped), in alternative embodiments, the substrate is asilicon on insulator (SOI) wafer. As an alternative, any other suitablesemiconductor material may be used for the substrate, for examplesemiconductor compound material such as gallium phosphide (GaP), indiumphosphide (InP), but also any suitable ternary semiconductor compoundmaterial or quaternary semiconductor compound material such as indiumgallium arsenide (InGaAs).

A semiconductor material, layer, region or the like may be understood ashaving moderate electrical conductivity, e.g. an electrical conductivity(measured at room temperature and constant electric field direction,e.g. constant electric field) in the range from about 10⁻⁶ S/m to about10⁶ S/m. An electrically conductive material, layer, region or the likemay be understood as having high electrical conductivity, e.g. anelectrical conductivity (measured at room temperature and constantelectric field direction, e.g. constant electric field) greater thanabout 10⁶ S/m, e.g. greater than about 10⁷ S/m. An electricallyinsulating material, layer, region or the like may be understood as poorhigh electrical conductivity, e.g. an electrical conductivity (measuredat room temperature and constant electric field direction, e.g. constantelectric field) less than about 10⁻⁶ S/m, e.g. less than about 10⁻¹⁰S/m.

According to various embodiments, a metal refers to a chemical element(e.g. a metalloid, a transition metal, a post-transition metal, analkali metal or an alkaline earth metal), such as tungsten (W), aluminum(Al), copper (Cu), nickel (Ni), magnesium (Mg), chromium (Cr), iron(Fe), zinc (Zn), tin (Sn), gold (Au), silver (Ag), iridium (Ir),platinum (Pt), indium (In), cadmium (Cd), bismuth (Bi), vanadium (V),titanium (Ti), palladium (Pd), or zirconium (Zr).

A metal alloy may include at least two a metals (e.g. two or more thantwo metals, e.g. in the case of an intermetallic compound) or at leastone metal (e.g. one or more than one metal) and at least one otherchemical element (e.g. a non-metal or a half metal). For example, ametal alloy may include or may be formed from at least one metal and atleast one non-metal (e.g. carbon (C) or nitrogen (N)), e.g. in the caseof steel or a nitride. For example, a metal alloy may include or may beformed from more than one metals (e.g. two or more metals), e.g. variouscompositions of gold with aluminum, various compositions of copper withaluminum, various compositions of copper and zinc (e.g. “brass”) or anvarious compositions of copper and tin (e.g. “bronze”), e.g. includingvarious intermetallic compounds.

According to various embodiments, a semiconductor device may include aninsulated gate bipolar transistor (IGBT). The semiconductor device mayfurther include a metallization layer, e.g. including or formed fromcopper.

According to various embodiments, potential defects in the at least onebarrier layer may be reduced by a self-organizing barrier layer.Illustratively, the self-organizing barrier layer may provide thecapability to seal the defects such that the reliability in diffusionseparation may be increased. The self-organizing barrier layer may beused instead of or in combination with conventional barrier layers.

According to various embodiments, the metallization layer may include orbe formed from a self-segregating composition, e.g. a compositionincluding one or more than one chemical element, e.g. one or moremetals. For example, a temperature to which a barrier layer is stable(break down temperature) may be increased by adding a self-segregatingalloying element (e.g. manganese) into a metallization layer, e.g. acopper metallization layer. Manganese may segregate from the copper athigher temperatures and may form a self-organizing barrier layer betweenthe copper metallization layer and the semiconductor material (e.g. Si).By way of example, if a conventional barrier layer includes defects, adiffusion of copper into the semiconductor material may be reduced oreven substantially eliminated by the manganese and needs much highertemperatures to be activated. Illustratively, the manganese may seal adefect in the conventional barrier layer.

According to various embodiments, the lifetime of the semiconductordevice may be increased and a deterioration of the semiconductor devicearising from defects (e.g. in a conventionally barrier layer) may bereduced or even substantially eliminated.

A metallization layer, e.g. a contact pad (e.g. including copper), mayinclude an alloying element (also referred to as self-segregatingalloying element) which is configured to diffuse to the surface of themetallization layer, e.g. by temperature activated self-segregation.Alternatively or additionally, a tendency of the alloying element toreact with the semiconductor material (e.g. silicon), e.g. forming abinary metallic compound of the semiconductor material (e.g. asilicide), may be configured to be low, e.g. minimal. Therefore, areaction at the interface to the semiconductor material may besuppressed by the alloying element. To reduce a reaction tendency of theof the alloying element with the semiconductor material anelectronegativity of the alloying element may be less than anelectronegativity of at least one of the host material or thesemiconductor material.

According to various embodiments, an electronegativity of a region ormaterial (e.g. of a chemical element in there) may be understood as achemical property that describes the tendency of an atom of the regionor the material to attract electrons (or electron density) towardsitself. The electronegativity may be affected by both its atomic number(of a region or material) and the distance at which its valenceelectrons reside from the charged nucleus. The higher the associatedelectronegativity of the region or material is, the more a chemicalelement or a compound of the region or material attracts electronstowards it.

Segregation may be understood to the enrichment of a constituent of amaterial (e.g. the self-segregating alloying element) at a surface, e.g.a free surface or an internal interface, of the material. Theconstituent may migrate from a central region of the material to aperipheral region of the material. The migration may be activated bytemperature, e.g. above room temperature.

The self-segregating alloying element may be disposed in a host material(e.g. mixed with it) to form a self-segregating composition. Theself-segregating composition may be a metastable composition, e.g. abovean equilibrium solubility and/or within a miscibility gap. For example,the self-segregating alloying element may be soluble in the hostmaterial up to the equilibrium solubility, wherein the self-segregatingcomposition may include a concentration of the self-segregating alloyingelement greater than the equilibrium solubility.

The alloying element and the host material may differ from each other inat least one of: a bulk crystal structure (e.g. in the range from aboutroom temperature to about the segregation temperature, e.g. to about400° C.), an atomic radius of more than 15%, an electronegativity ofmore than 15%.

Furthermore, the self-segregating composition may include at least oneof more than one phase, an eutectic, or a miscibility gap.

FIG. 1A and FIG. 1B illustrate a semiconductor device according tovarious embodiments, in a method according to various embodiments in aschematic cross sectional view or side view.

The method may include in 100 a forming a metallization layer 104 over asemiconductor region 102. The metallization layer 104 may include or beformed from a self-segregating composition 104 a, 104 h. A physicalvapor deposition, e.g. sputtering, may be used for forming themetallization layer 104.

The self-segregating composition may include or be formed from a hostmaterial and an alloying element 104 a (self-segregating alloyingelement 104 a). The alloying element 104 a may include or be formed froma first metal. Alternatively or additionally, the host material mayinclude or be formed from a second metal, e.g. different from the firstmetal.

The self-segregating composition 104 a, 104 h may be disposedstoichiometric. Alternatively or additionally, the self-segregatingcomposition 104 a, 104 h may include or be formed from alternatingsublayers differing in their stoichiometry (e.g. alloying element richor host material rich).

In a schematic diagram 151 a, a concentration 104 c (e.g. an atomicconcentration) of the alloying element 104 a is illustrated over avertical position 105 before activating a segregation. The concentration104 c of the alloying element 104 a in the metallization layer 104 maybe at least one of substantially homogeneous in the metallization layer104 (e.g. less than 30% variation), or greater than a concentration 104c of the alloying element 104 a in the semiconductor region 102.

The metallization layer 104 may be in physical contact to thesemiconductor region 102, e.g. at an interface 110. Alternatively oradditionally, at least one further barrier layer may be formed betweenthe metallization layer 104 and the semiconductor region 102 (see FIG.2A).

The method may include, in 100 b, activating a segregation of thealloying element 104 a from the self-segregating composition 104 a, 104h to form a self-organizing barrier layer 106 between the metallizationlayer 104 (e.g. the host material 104 h) and the semiconductor region102 (e.g. the semiconductor material 412). Activating the segregationmay include activating a migration 104 m of the alloying element 104 ainto a direction of the interface 110 between the metallization layer104 and the semiconductor region 102. Alternatively or additionally,activating the segregation may include reducing a concentration (e.g.spatially averaged) of the alloying element 104 a in the metallizationlayer 104. Alternatively or additionally, activating the segregation mayinclude enriching the alloying element 104 a between the metallizationlayer 104 (e.g. the host material 104 h) and the semiconductor region102 (e.g. the semiconductor material 412).

In a schematic diagram 151 b a concentration 104 c (e.g. an atomicconcentration) of the alloying element 104 a is illustrated over avertical position 105 after activating the segregation. Theconcentration 104 c of the alloying element 104 a in the metallizationlayer 104 may be at least one of greater than a concentration 104 c ofthe alloying element 104 a in the semiconductor region 102, or greaterthan a concentration 104 c of the alloying element 104 a in themetallization layer 104.

A concentration (first concentration, e.g. spatially averaged) of thealloying element 104 a in the metallization layer 104 (e.g. in theself-segregating composition) before the activating the segregation maybe greater than a concentration (second concentration, e.g. spatiallyaveraged) of the alloying element 104 a in the metallization layer 104(e.g. in the self-segregating composition) after the activating thesegregation. Alternatively or additionally, at least one of the firstconcentration or the second concentration may be less than aconcentration (third concentration, e.g. e.g. spatially averaged) of thealloying element 104 a in the self-organizing barrier layer 106.

The first concentration (e.g. spatially averaged) may be in the rangefrom about 0.5 atomic percent (at %) to about 50 at %, e.g. in the rangefrom about 1 at % to about 40 at %, e.g. in the range from about 2 at %to about 30 at %, e.g. in the range from about 5 at % to about 25 at %,e.g. in the range from about 5 at % to about 20 at %, e.g. about 10 at%.

Alternatively or additionally, a concentration of the self-segregatingcomposition in the self-segregating composition in the metallizationlayer 104 may be greater than about 70 at %, e.g. greater than about 80at %, e.g. greater than about 90 at %, e.g. greater than about 95 at %,e.g. greater than about 99 at %, e.g. about 100 at %. In other words,the metallization layer 104 may be substantially formed from theself-segregating composition.

The second concentration (e.g. spatially averaged) may be less thanabout 50 at %, e.g. less than about 40 at %, e.g. less than about 30 at%, e.g. less than about 20 at %, e.g. less than about 10 at %, e.g. lessthan about 5 at %, e.g. less than about 2 at %, e.g. less than about 0.5at %, e.g. less than about 0.1 at %.

The third concentration (e.g. spatially averaged) 106 may be greaterthan about 70 at %, e.g. greater than about 80 at %, e.g. greater thanabout 90 at %, e.g. greater than about 95 at %, e.g. greater than about99 at %, e.g. about 100 at %. In other words, the self-organizingbarrier layer 106 may be substantially formed from the alloying element104 a.

Alternatively or additionally, the self-organizing barrier layer 106 maybe substantially formed from a compound (also referred to as barriercompound) including the alloying element 104 a and a semiconductor (alsoreferred to as semiconductor material) of the semiconductor region. Inother words, a concentration of at least one of the barrier compound (ora sum of the barrier compound and the alloying element 104 a) in theself-organizing barrier layer 106 may be greater than about 70 at %,e.g. greater than about 80 at %, e.g. greater than about 90 at %, e.g.greater than about 95 at %, e.g. greater than about 99 at %, e.g. about100 at %. For example, the barrier compound may include or be formedfrom a binary metallic compound of the semiconductor material, e.g. asilicide.

The alloying element 104 a may include or be formed from at least oneof: manganese, tantalum, chromium, tungsten, and/or molybdenum.

A thickness 104 t of the metallization layer 104 (e.g. at least one ofbefore the activating the segregation or after the activating thesegregation) may be greater than about ten times a thickness 106 t ofthe self-organizing barrier layer 106, e.g. greater than about twentytimes a thickness 106 t of the self-organizing barrier layer 106, e.g.greater than about thirty times a thickness 106 t of the self-organizingbarrier layer 106, e.g. greater than about fifty times a thickness 106 tof the self-organizing barrier layer 106, e.g. greater than abouthundred times a thickness 106 t of the self-organizing barrier layer106.

The thickness 104 t of the metallization layer 104 may decrease duringthe activating the segregation. In other words, the thickness 104 t ofthe metallization layer 104 before the activating the segregation may begreater than the thickness 104 t of the metallization layer 104 afterthe activating the segregation).

The thickness 106 t of the self-organizing barrier layer 106 mayincrease during the activating the segregation.

Furthermore, the thickness 106 t of the self-organizing barrier layer106 may be in the range from about 1 nanometer (nm) to about 50 nm, e.g.in the range from about 1 nm to about 20 nm, e.g. greater than about 2nm, e.g. greater than about 5 nm, and/or less than about 15 nm, e.g.less than about 10 nm.

According to various embodiments, the thickness 104 t of themetallization layer 104 may be in the range from about 100 nm to about 1micrometer (m), e.g. greater than about 200 nm, e.g. greater than about250 nm, and/or less than about 0.75 μm, e.g. less than about 0.5 μm.

Alternatively or additionally, activating the segregation may includeforming a concentration gradient of the alloying element 104 a in themetallization layer 104 pointing into the direction of the semiconductorregion 102.

According to various embodiments, the self-organizing barrier layer 106may be in physical contact to at least one of the metallization layer104 or the semiconductor region 102.

According to various embodiments, at least one of the alloying element104 a or the self-segregating composition 104 a, 104 h may be configuredsuch that a segregation of the alloying element 104 a from themetallization layer 104 (e.g. the host material 104 h) starts at a lowertemperature than a reaction of the metallization layer 104 (e.g. thehost material 104 h) with the semiconductor region 102 (e.g. thesemiconductor material). In other words, a temperature activating asegregation (also referred to as segregation temperature) of thealloying element from the metallization layer may be less than atemperature activating a reaction (also referred to as reactiontemperature) of the metallization layer 104 (e.g. the host material 104h) with the semiconductor region 102 (e.g. the semiconductor material).

Alternatively or additionally, at least one of the alloying element 104a or the self-segregating composition 104 a, 104 h may be configuredsuch that a layer formation velocity (thickness 106 t per time) of theself-organizing barrier layer 106 is greater than a layer formationvelocity driven by a reaction of the metallization layer 104 (e.g. thehost material 104 h) with the semiconductor region 102 (e.g. thesemiconductor material). In other words, the alloying element 104 a maybe configured to segregate from the metallization layer 104 (e.g. thehost material 104 h) faster than the metallization layer 104 (e.g. thehost material 104 h) chemically reacts with the semiconductor region 102(e.g. the semiconductor material).

The segregation temperature may be less than about 400° C., e.g. lessthan about 350° C., e.g. less than about 300° C., e.g. less than about250° C., e.g. less than about 200° C., e.g. less than about 190° C.,e.g. less than about 180° C., e.g. less than about 170° C., e.g. lessthan about 160° C., e.g. less than about 150° C., alternatively oradditionally (and/or), more than about room temperature, e.g. more thanabout 100° C.

The method may include, in 100 b, heating the metallization layer 104 toa temperature greater than the segregation temperature to activate thesegregation of the alloying element 104 a from the metallization layer104 (e.g. the host material 104 h).

FIG. 2A and FIG. 2B illustrate a semiconductor device according tovarious embodiments, in a method according to various embodiments in aschematic cross sectional view or side view.

The method may include, in 200 a, forming at least one further barrierlayer 204 (in other words, one or more further barrier layers 204)between the metallization layer 104 and the semiconductor region 102.The metallization layer 104 may be formed over the at least one furtherbarrier layer 204.

The at least one further barrier layer 204 may include or be formed froma barrier layer stack. For example, the at least one further barrierlayer 204 may be formed using at least one of physical vapor deposition(PVD), e.g. sputtering, or chemical vapor deposition (CVD).

The at least one further barrier layer 204 may include or be formed fromat least one of titanium or tungsten.

By way of example, the at least one further barrier layer 204 mayinclude or be formed from at least one of the following layers: a firstbarrier layer including or formed from titanium and tungsten (e.g. byPVD), a second barrier layer including or formed from tungsten (e.g. byCVD) and a third barrier layer including or formed from titanium andtungsten (e.g. by PVD). By way of example, the second barrier layer maybe disposed between the first and third barrier layer.

If the at least one further barrier layer 204 includes one or moredefects 204 d, a separation efficiency of the at least one furtherbarrier layer 204 may be reduced in the one or more defects 204 d. Byway of example, the one or more defects 204 d may include or be formedfrom one or more openings through which at least one of themetallization layer 104 (e.g. the host material 104 h) may physicallycontact the semiconductor region 102, the host material 104 h migratesthrough or the semiconductor material 412 migrates through.

According to various embodiments, the method may include, in 200 b,sealing (also referred to as healing) the one or more defects 204 d bysegregating the alloying element 104 a from the metallization layer 104at least one of in or on the one or more defects 204 d. Theself-organizing barrier layer 106 may include or be formed from at leastone of the alloying element 104 a or the barrier compound. Theself-organizing barrier layer 106 may be formed at least one of in or onthe one or more defects 204 d.

The segregation may be activated as described before, e.g. by heatingthe metallization layer 104 over the segregation temperature.

The self-organizing barrier layer 106 may be in physical contact to atleast one of the metallization layer 104, the at least one furtherbarrier layer 160 or the semiconductor region 102. At least one of theself-organizing barrier layer 106 or the at least one further barrierlayer 204 may separate the metallization layer 104 (e.g. the hostmaterial 104 h) from the semiconductor region 102.

FIG. 3A and FIG. 3B respectively illustrate a semiconductor deviceaccording to various embodiments, in a method according to variousembodiments in a schematic cross sectional view or side view.

The semiconductor region 102 may be part of a wafer, e.g. a siliconwafer.

The method may include, in 300 a and in 300 b, cleaning thesemiconductor region 102, e.g. by chemical wet etching. Alternatively oradditionally, the method may include in 300 a and in 300 b exposing thesemiconductor material 412 of the semiconductor region 102, e.g. byremoving a native oxide of the semiconductor material from thesemiconductor region 102. By way of example, exposing the semiconductormaterial may include at least one of plasma etching (e.g. in argon) orsputter etching (also referred to as Sputter-Preclean).

The method may further include, in 300 a, forming a metallization layer104, e.g. from copper, on the semiconductor region 102 (e.g. free of thealloying element 104 a), e.g. by sputtering copper on the semiconductorregion 102.

The method may further include, in 300 b, forming a metallization layer104, e.g. from a copper-manganese alloy, on the semiconductor region102, e.g. by sputtering the copper-manganese alloy on the semiconductorregion 102. A concentration of manganese in the copper-manganese alloymay be about 10 at. %.

The method may include, in 300 a and 300 b, heating the semiconductordevice, e.g. for further processing. During the heating thesemiconductor device, a chemical analysis (e.g. secondary ion massspectrometry) may reveal at least one of the segregation temperature orthe reaction temperature. Alternatively or additionally, a resistivitymeasurement may reveal a formation of a binary metallic compounddisposed between the metallization layer 104 and the semiconductorregion 102, e.g. a silicide formation, and therefore may indicate thereaction temperature.

FIG. 4A and FIG. 4B respectively show a diagram 400 a illustrating achemical analysis of a region including the interface 110 (marked by aline at its estimated position for orientation) between themetallization layer 104 and the semiconductor region 102 by secondaryion mass spectrometry. The diagram 400 a illustrates an intensityparameter 402 representing counts of secondary electrons which indicatea concentration (e.g. atomic concentration) over a sputter timeparameter 404 representing depth position 105.

The method may include disposing a metallization layer 104 over thesemiconductor region 102. The metallization layer 104 may include or beformed from the host material 104 h. The semiconductor region 102 mayinclude or be formed from the semiconductor material 412. Themetallization layer 104 and the semiconductor region 102 may be free ofany interdiffusion, indicated by the sharp drop of the concentrations402 at the interface 110. The metallization layer 104 may besubstantially free of the semiconductor material 412 of thesemiconductor region 102. The semiconductor region 102 may besubstantially free of the host material 104 h.

The method may include heating the metallization layer 104 for 45minutes at 180° C. (as shown in a diagram 400 b). As visible from thecomparison, a concentration of the host material 104 h proximate theinterface 110 may increase due to a temperature activated interdiffusionof the host material 104 h and the semiconductor material 412. In otherwords, the metallization layer 104 and the semiconductor region 102 maypartially diffuse into each other, indicated by the broadened drop ofthe concentrations 402 at the interface 110.

FIG. 5A and FIG. 5B respectively show a schematic diagram, similar toFIG. 4A and FIG. 4B.

As shown in a diagram 500 a in FIG. 5A, the method may include heatingthe metallization layer 104 for 90 minutes at 180° C. As visible fromthe comparison, the semiconductor material 412 may be migrated into themetallization layer 104 and the host material 104 h may be migrated intothe semiconductor region 102. The line 502 may represent a reactionproduct 502 (also referred to as reaction compound 502) of thesemiconductor material 412 with the host material 104 h, e.g. a binarymetallic compound of the semiconductor material (e.g. copper silicide).This may indicate a chemical reaction starting proximate the interface110. The formation of the reaction compound 502 may also be indicatedmay the double maximum in the concentration 402 of the host material 104h proximate the interface 110, indicating a local enrichment of the hostmaterial 104 h defined by the stoichiometry of reaction compound 502.

As shown in a diagram 500 b in FIG. 5B, the method may include heatingthe metallization layer 104 for 30 minutes at 200° C. As visible fromthe comparison, the semiconductor material 412 with the host material104 h may be fully reacted to the reaction compound 502 (e.g. coppersilicide). This may also be indicated by the homogeneous distribution ofhost material 104 h and the semiconductor material 412, illustrativelyfixed by the stoichiometry of the reaction compound 502.

As illustrated in FIG. 4A and FIG. 4B, the reaction temperature may beless than 200° C., e.g. about 180° C.

FIG. 6A and FIG. 6B respectively show a schematic diagram, similar toFIG. 4A and FIG. 4B.

As shown in a diagram 600 a in FIG. 6A, the method may include disposinga metallization layer 104 over the semiconductor region 102. Themetallization layer 104 may include or be formed from the host material104 h and the alloying element 104 a, e.g. a homogeneousself-segregating composition of the host material 104 h and the alloyingelement 104 a. The semiconductor region 102 may include or be formedfrom the semiconductor material 412. The metallization layer 104 and thesemiconductor region 102 may be free of any interdiffusion, indicated bythe sharp drop of the concentrations 402 at the interface 110. Themetallization layer 104 may be substantially free of the semiconductormaterial 412 of the semiconductor region 102. The semiconductor region102 may be substantially free of the host material 104 h.

As shown in a diagram 600 b in FIG. 5B, the method may include heatingthe metallization layer 104 for 30 minutes at 200° C., similar to 500 b.As visible from the comparison, a concentration of the host material 104h and the alloying element 104 a proximate the initial interface may bemore stable than for 500 b. As indicated by the deviated maximum in theconcentration of the host material 104 h and the alloying element 104 a,the alloying element 104 a is migrated towards the semiconductor region102, e.g. due to a temperature activated segregation of the alloyingelement 104 a from the host material 104 h. In other words, the alloyingelement 104 a segregates from the metallization layer 104. The alloyingelement 104 a may form a chemically stable interlayer 106 (also referredto as self-organizing barrier layer 106). The interlayer 106 mayeffectively separate the host material 104 h from the semiconductormaterial 412 and may be configured to act as diffusion barrier.

An interface of the self-organizing barrier layer 106 and thesemiconductor region 102 may be substantially free of the host material104 h. An interface of the self-organizing barrier layer 106 and themetallization layer 104 may be substantially free of the semiconductormaterial 412. The metallization layer 104 may be substantially free ofthe semiconductor material 412 of the semiconductor region 102 after theactivating the segregation. The semiconductor region 102 may besubstantially free of the host material 104 h after the activating thesegregation.

FIG. 7A and FIG. 7B respectively show a schematic diagram, similar toFIG. 4A and FIG. 4B.

As shown in a diagram 700 a in FIG. 7A, the method may include heatingthe metallization layer 104 for 90 minutes at 220° C. As visible fromthe comparison, a concentration of the host material 104 h and thealloying element 104 a proximate the initial interface 110 may be morestable than for 500 b. As indicated by the deviation of the maximumconcentration of the host material 104 h and the alloying element 104 a,the alloying element 104 a is migrated towards the semiconductor region102, e.g. due to a temperature activated segregation of the alloyingelement 104 a from the host material 104 h. The interlayer 106 mayeffectively separate the host material 104 h from the semiconductormaterial 412 and may be configured to act as diffusion barrier.

An interface of the self-organizing barrier layer 106 and thesemiconductor region 102 may be substantially free of the host material104 h. There may occur a small diffusion of the semiconductor materialinto the metallization layer 104. However, a concentration of thesemiconductor material 412 in metallization layer 104 may be within asolubility range defined by the semiconductor material 412 and themetallization layer 104. The solubility range may include a maximum,also referred to as solubility limit. The concentration of thesemiconductor material 412 in metallization layer 104 may be less thanthe solubility limit of the semiconductor material 412 in the hostmaterial 104 h. Therefore, substantially no reaction of thesemiconductor material 412 with the host material 104 h may beactivated.

As shown in a diagram 700 b in FIG. 7B, the method may include heatingthe metallization layer 104 for 30 minutes at 240° C. As visible fromthe comparison, the semiconductor material 412 and the host material 104h may be reacted partially to the reaction compound 502, e.g. a binarymetallic compound 502 of the semiconductor material (e.g. coppersilicide). This may indicate that the interface layer 106 is brokendown.

As illustrated, the break down temperature of the self-organizingbarrier layer 106 may be greater than the reaction temperature, e.g. bya minimum of 20° C., e.g. by a range from about 40° C. to about 60° C.

FIG. 8A and FIG. 8B respectively show a schematic diagram, similar toFIG. 4A and FIG. 4B.

As shown in a diagram 800 a in FIG. 8A, the method may include heatingthe metallization layer 104 to activate a segregation of the alloyingelement 104 a from the host material 104 h. FIG. 8A illustrates acomparison of the spatially distributed concentration 402 of thealloying element 104 a for various heating times at 200° C., indicatinga layer formation velocity (thickness per time) of the self-organizingbarrier layer 106 driven by the self-segregation.

The line 802 illustrates the spatially distributed concentration 402 ofthe alloying element 104 a before heating. The line 804 illustrates thespatially distributed concentration 402 of the alloying element 104 aafter heating for various times in the range from about 30 minutes toabout 75 minutes. As visible, no significant change is noticeablebetween the various heating times, indicating that a full equilibrium(of the formation of the self-organizing barrier layer 106) is reachedby less than about 30 minutes.

As shown in a diagram 800 b in FIG. 8B, the method may include heatingthe metallization layer 104 to activate a segregation of the alloyingelement 104 a from the host material 104 h. In FIG. 8A a comparison ofthe spatially distributed concentration 402 of the alloying element 104a is illustrated for various heating times at 220° C., indicating alayer formation velocity (thickness per time) of the self-organizingbarrier layer 106 driven by the self-segregation.

The line 802 illustrates the spatially distributed concentration 402 ofthe alloying element 104 a before heating. The line 806 illustrates thespatially distributed concentration 402 of the alloying element 104 aafter heating for various times in the range from about 15 minutes toabout 45 minutes. As visible, no significant change is noticeablebetween the various heating times, indicating that the full equilibriumreached by less than about 15 minutes.

As visible in the comparison with 500 a and 500 b, the layer formationvelocity of the self-organizing barrier layer 106 is greater than alayer formation velocity of the reaction product from the semiconductormaterial 412 and the host material 104 h.

Further, the self-organizing barrier layer 106 may be time-stable. Atime stability of the self-organizing barrier layer 106 (at a certaintemperature and/or at a certain heating time) may be greater than a timestability of the interface 110 between the metallization layer 104 (e.g.the host material 104 h) and semiconductor region 102 (e.g. thesemiconductor material 412).

According to various embodiments, the self-organizing barrier layer 106may be time-stable for more than about 15 minutes (e.g. at 200° C. or220° C.), e.g. for more than about 30 minutes (e.g. at 200° C. or 220°C.), e.g. for more than about 45 minutes (e.g. at 200° C. or 220° C.),e.g. for more than about 60 minutes (e.g. at 200° C. or 220° C.), e.g.for more than about 75 minutes (e.g. at 200° C. or 220° C.).

FIG. 9A and FIG. 9B respectively show a schematic diagram, similar toFIG. 4A and FIG. 4B.

As shown in a diagram 900 a in FIG. 9A, the method may include heatingthe metallization layer 104 to activate a segregation of the alloyingelement 104 a from the host material 104 h. In FIG. 9A a comparison ofthe spatially distributed concentration 402 of the semiconductormaterial 412 is illustrated for various heating times at 200° C.,indicating a diffusion velocity (length per time) of the semiconductormaterial 412 106 driven by temperature activated diffusion.

The line 902 illustrates the spatially distributed concentration 402 ofthe semiconductor material 412 before heating. The line 904 illustratesthe spatially distributed concentration 402 of the semiconductormaterial 412 after heating at 200° C. for various times in the rangefrom about 30 minutes to about 75 minutes. As visible, a slightdiffusion of the semiconductor material 412 into the metallization layer104 occurs, but no significant increase of the diffusion length isnoticeable with increasing heating time, indicating that the fullequilibrium reached by a maximum of 30 minutes.

As shown in a diagram 900 b in FIG. 9B, the method may include heatingthe metallization layer 104 to activate a segregation of the alloyingelement 104 a from the host material 104 h. In FIG. 9B a comparison ofthe spatially distributed concentration 402 of the semiconductormaterial 412 is illustrated for various heating times at 220° C.,indicating a diffusion velocity (length per time) of the semiconductormaterial 412 106 driven by temperature activated diffusion.

The line 902 illustrates the spatially distributed concentration 402 ofthe semiconductor material 412 before heating. The line 906 illustratesthe spatially distributed concentration 402 of the semiconductormaterial 412 after heating at 220° C. for various times in the rangefrom about 15 minutes to about 45 minutes. As shown, a slight diffusionof the semiconductor material 412 into the metallization layer 104occurs, but no significant increase of the diffusion length isnoticeable with increasing heating time, indicating that the fullequilibrium reached by a maximum of 15 minutes.

As shown in comparison with 800 a and 800 b, the diffusion velocity ofthe semiconductor material 412 (e.g. at least one of into themetallization layer 104 or out of the semiconductor region 102) may beless than the diffusion velocity of the alloying element 104 a (e.g. atleast one of out of the metallization layer 104 or into thesemiconductor region 102). Alternatively or additionally, the diffusionvelocity of the host material 104 h (e.g. at least one of out of themetallization layer 104 or into the semiconductor region 102) may beless than the diffusion velocity of the alloying element 104 a (e.g. atleast one of out of the metallization layer 104 or into thesemiconductor region 102).

FIG. 10A and FIG. 10B respectively show a schematic diagram. Diagram1000 a shows a chemical analysis (e.g. energy-dispersive X-rayspectroscopy) obtained from the interface between the self-organizingbarrier layer 106 and the metallization layer 104 in the case of amanganese barrier layer 106, a silicon semiconductor material 412 and acopper metallization layer 104. The diagram 1000 a illustrates anintensity parameter 1002 representing a concentration and an energyparameter 1004 representing a specific chemical element. Strong peaksindicate the presence of copper (Cu), manganese (Mn) and silicon (Si).

FIG. 10B shows a phase diagram 1000 b in dependency of temperature 1012and a concentration of 1014 manganese in copper.

From this analysis the chemical composition 1004 proximate theself-organizing barrier layer 106 may be estimated to be about 62.5 at.% manganese and 37.5 at. % silicon, which may indicate the formation ofa manganese silicide compound (Mn₅Si₃) and a gamma-phase ofmanganese-copper, see diagram 1000 b.

FIG. 11 shows a diagram 1100 illustrating a specific resistance 1102 (inμOhm·cm) in dependency of the temperature 1104 to which themetallization layer 104 is heated. An increase of the specificresistivity 1102 may indicate a reaction, e.g. between the semiconductormaterial 412 and at least one of the host material 104 h or the alloyingelement 104 a, e.g. a formation of a binary metallic compound, e.g. asilicide formation, and therefore may indicate the reaction temperature.

Line 1110 represents a first concentration (before the activating thesegregation), in other words, a concentration (e.g. spatially averaged)of the alloying element 104 a in the metallization layer 104, of lessthan 0.5 at: %, e.g. about 0 at: %, line 1112 represents a firstconcentration of about 2 at: %, line 1115 represents a firstconcentration of about 5 at: %, and line 1120 represents a firstconcentration of about 10 at: %.

As shown by line 1110, the reaction temperature may be about 180° C. Asby lines 1112, 1115, 1120 a first concentration greater than about 0.5at: % may suppress the reaction between the host material 104 h and thesemiconductor material 412 up to a temperature greater than about 225°C.

A specific resistance 1102 between the metallization layer 104 and thesemiconductor region 102 may be less than about 70 μOhm·cm, e.g. lessthan about 60 μOhm·cm, e.g. less than about 50 μOhm·cm, e.g. less thanabout 40 μOhm·cm, e.g. less than about 30 μOhm·cm, e.g. at least one ofduring or after activating the segregation and/or at least one of duringor after heating the metallization layer 104 to a temperature greaterthan about 200° C., e.g. greater than about 220° C.

A specific resistance 1102 between the metallization layer 104 and thesemiconductor region 102 may be substantially constant (variate lessthan 30%) during the activating of the segregation. Alternatively oradditionally, the specific resistance 1102 between the metallizationlayer 104 and the semiconductor region 102 may be substantially constantup to a minimum temperature of about 200° C., e.g. a minimum temperatureof about 220° C.

A temperature activating a reaction of the semiconductor material 412with the host material 104 h may be less than a temperature activating areaction of the semiconductor material 412 with the alloying element 104a. Alternatively or additionally, a temperature activating a reaction ofthe semiconductor material 412 with the host material 104 h may beincreased by the self-organizing barrier layer 106, e.g. by a minimum of20° C., e.g. by a range from about 40° C. to about 60° C.

FIG. 12 shows a semiconductor device 1200 according to variousembodiments, in a method according to various embodiments in a schematiccross sectional view or side view in the triple point 1201, in which theat least one further barrier layer 204, the semiconductor region 102 andthe metallization layer 104 contact each other, wherein view 1200 agives a detailed view and view 1200 b gives an overview.

The semiconductor device may include an intermediate oxide layer 1202between the metallization layer 104 and the semiconductor region 102.The intermediate oxide layer 1202 may include an opening 1202 o in whichthe metallization layer 104 is extended.

If the segregation is not activated, a defect 204 d may lead to damageof the semiconductor device 1300. The at least one further barrier layer204 may include a defect 204 d in which a reaction compound 502 may beformed from the host material 104 h and the semiconductor material 412which propagates between the at least one further barrier layer 204 andthe semiconductor region 102 inducing further damage.

FIG. 13 illustrates a semiconductor device 1300 according to variousembodiments, in a method according to various embodiments in a schematiccross sectional view or side view, wherein view 1200 a gives a detailedview, 1300 a gives a microstructural view, and view 1200 b gives anoverview.

If the segregation is activated, the self-organizing barrier layer 106may be formed between the metallization layer 104 and the semiconductorregion 102 suppressing further damage of the semiconductor device 1300.

FIG. 14 shows a semiconductor device 1400 according to variousembodiments, in a method according to various embodiments in a schematiccross sectional view or side view.

The semiconductor region 102 may include a doped region 102 d (dopedsemiconductor region 102 d) proximate the metallization layer 104.

The self-organizing barrier layer 106 may also extend between theintermediate oxide layer 1202 and the metallization layer 104.

The metallization layer 104 may include a first sublayer 104 b includingor formed from the self-segregating composition and a second sublayer104 t including or formed from the host material 104 h. Illustratively,the first sublayer 104 b may serve as seed layer.

FIG. 15 illustrates a method 1500 according to various embodiments in aschematic flow diagram.

The method may include, in 1502, forming a metallization layer over asemiconductor region, wherein the metallization layer may include or beformed from a self-segregating composition, which may include or beformed from an alloying element and a host material. The method mayfurther include, in 1504, activating a segregation of the alloyingelement from the self-segregating composition to form a self-organizingbarrier layer between the host material and the semiconductor region.

FIG. 16 illustrates a method 1600 according to various embodiments in aschematic flow diagram.

The method may include, in 1602, forming a metallization layer over abarrier layer, wherein the metallization layer may include or be formedfrom an alloying element configured to be self-segregating from themetallization layer. The method may further include, in 1604, healing(in other words, sealing) a defect in the barrier layer by segregatingthe alloying element from the metallization layer at least one of in orover the defect.

FIG. 17A illustrates a semiconductor device 1700 a according to variousembodiments in a method according to various embodiments in a schematiccross sectional view or side view.

According to various embodiments, the semiconductor device 1700 a mayinclude a plurality of semiconductor circuit elements 1702 a, 1702 b,1702 c electrically connected 1904 in parallel to each other.

The semiconductor device 1900 a may include a first metallization layer1922 on the first side 102 t of the semiconductor region 102. Eachsemiconductor circuit element of the plurality of semiconductor circuitelements 1702 a, 1702 b, 1702 c may be electrically connected 1904 tothe first metallization layer 1922. Alternatively or additionally, thesemiconductor device 1900 a may include a second metallization layer1822 on the second side 102 b of the semiconductor region 102. Eachsemiconductor circuit element of the plurality of semiconductor circuitelements 1702 a, 1702 b, 1702 c may be electrically connected 1904 tothe second metallization layer 1822.

According to various embodiments, each semiconductor circuit element ofthe plurality of semiconductor circuit elements 1702 a, 1702 b, 1702 cmay include or be formed from a diode structure or a transistorstructure (also referred to as transistor cell). According to variousembodiments, the plurality of semiconductor circuit elements 1702 a,1702 b, 1702 c may be part of or form a power semiconductor circuitelement 1702.

According to various embodiments, each semiconductor circuit element ofthe plurality of semiconductor circuit elements 1702 a, 1702 b, 1702 c(e.g. the power semiconductor circuit element 1702) may include or beformed from a vertical structure. A vertical structure may be understoodas providing a current flow from the first side of the semiconductorregion 102 to the second side 102 b of the semiconductor region 102 orvice versa.

According to various embodiments, each semiconductor circuit element ofthe plurality of semiconductor circuit elements 1702 a, 1702 b, 1702 c(e.g. the power semiconductor circuit element 1702) may include at leastone gate contact pad. The at least one gate contact pad may be providedby (e.g. formed from) the first metallization 1922.

According to various embodiments, a first self-organizing barrier layer106 a may be formed between the first metallization layer 1922 and thesemiconductor region 102. Alternatively or additionally, a secondself-organizing barrier layer 106 b may be formed between the secondmetallization layer 1822 and the semiconductor region 102.

FIG. 17B illustrates a semiconductor device 1700 b according to variousembodiments in a method according to various embodiments in a schematiccross sectional view or side view.

The semiconductor device 1700 b may include at least one a semiconductorcircuit element 1702 a, 1702 b, 1702 c, e.g. a power semiconductorcircuit element 1702, formed at least one of over or in thesemiconductor region.

According to various embodiments, the semiconductor device 1700 a mayinclude at least one first contact pad 1706 (e.g. at least one collectorcontact pad 1706). The at least one first contact pad 1706 may beelectrically connected to the at least one semiconductor circuit element1702 a, 1702 b, 1702 c, 1702. The at least one first contact pad 1706may be formed by structuring the second metallization layer 1822.

Alternatively or additionally, the semiconductor device 1700 a mayinclude at least one second contact pad 1708 (e.g. a source/draincontact pad 1706) formed in electrical contact 1710 to the at least onesemiconductor circuit element 1702 a, 1702 b, 1702 c, 1702. The at leastone second contact pad 1708 optionally may include a gate contact pad,e.g. which may be formed electrically insulated from the semiconductorregion 102. The at least one second contact pad 1708 may be formed bystructuring the first metallization layer 1922.

According to various embodiments, the semiconductor circuit element 1702a, 1702 b, 1702 c, 1702 may include or be formed from insulated-gatebipolar transistor.

According to various embodiments, a first self-organizing barrier layer106 a may be formed between the at least one second contact pad 1708 andthe semiconductor region 102. Alternatively or additionally, a secondself-organizing barrier layer 106 b may be formed between the at leastone first contact pad 1706 and the semiconductor region 102.

FIG. 18A illustrates a semiconductor device 1800 a according to variousembodiments in a method according to various embodiments in a schematiccross sectional view or side view, e.g. a semiconductor circuit element1702 a, 1702 b, 1702 c, e.g. a power semiconductor circuit element 1702.

The semiconductor device 1800 a may include a doped semiconductor region1081 (doped collector region 1081) formed on a second side 102 b of thesubstrate. The doped collector region 1081 may include or be formed froma first doping type.

The semiconductor device 1800 a may further include a first contact pad1706 in form of a collector contact pad 1706 (e.g. a drain contact pad).The first contact pad 1706 may electrical contact the doped collectorregion 1081. The first contact pad 1706 may include or be formed from ametallization layer.

Further, the semiconductor device 1800 a may include a first dopedregion 2006 (doped first semiconductor region 2006). The first dopedregion 2006 may include or be formed from a base region. The first dopedregion 2006 may include (e.g. a dopant having) a doping type equal tothe doped collector region 1081 (in other words, the dopant of the dopedcollector region 1081), e.g. the first doping type. The semiconductordevice 1800 a may further include a second contact pad 1708 a electricalcontacting the first doped region 2006. The second contact pad 1708 amay include or be formed from an emitter contact pad 1708 a (e.g. asource contact pad 1708 a). The second contact pad 1708 a may include orbe formed from a metallization layer.

Further, the semiconductor device 1800 a may include a second dopedregion 2004 (doped second semiconductor region 2004) formed between thefirst doped region 2006 and the doped collector region 1081. The seconddoped region 2004 may include or be formed from a drift region. Thesecond doped region 2004 may include a doping type (second doping type)different from the doped collector region 1081, e.g. a dopant having thesecond doping type. The second doped region 2004 may include anepitaxially formed layer.

The semiconductor device 1800 a may further include a further secondcontact pad 1708 b. The further second contact pad 1708 b may include orbe formed from a gate contact pad 1708 b. The further second contact pad1708 b may be formed electrical insulated from the second doped region2004, e.g. by an electrically insulating layer formed between thefurther second contact pad 1708 b and the second doped region 2004. Thefurther second contact pad 1708 b may include or be formed from ametallization layer.

Further, the semiconductor device 1800 a may include a third dopedregion 2008 (doped third semiconductor region 2008). The third dopedregion 2008 may include or be formed from an emitter region. The thirddoped region 2008 may include (e.g. a dopant having) a doping typedifferent from the doped collector region 1081, e.g. the second dopingtype. A dopant concentration of the third doped region 2008 may begreater than of the second doped region 2004.

Optionally, the semiconductor device 1800 a may include a fourth dopedregion 2002 (doped fourth semiconductor region 2002) between the seconddoped region 2004 and the doped collector region 1081. The fourth dopedregion 2002 may include or be formed from a field stop region. Thefourth doped region 2002 may include a dopant having a doping typedifferent from the doped collector region 1081. The fourth doped region2002 may include a dopant concentration higher than the second dopedregion 2004.

According to various embodiments, the first doping type may be ann-doping type and the second doping type may be a p-doping type.Alternatively, the first doping type may be the p-doping type and thesecond doping type may be the n-doping type.

The semiconductor device 1800 a, e.g. a semiconductor circuit element1702 a, 1702 b, 1702 c may include or be formed from a transistorstructure, e.g. a planar transistor structure (providing a verticalcurrent flow). A transistor structure may include or be formed from aplurality of p-n junctions (e.g. more than one). A p-n junction may beformed by an interface of two doped regions having different dopingtypes, e.g. an interface between at least one the following: the firstdoped region 2006 and the second doped region 2004; the first dopedregion 2006 and the third doped region 2008; the second doped region2004 and the doped collector region 1081; the second doped region 2004and the fourth doped region 2002 (if present).

According to various embodiments, the semiconductor device 1800 a, e.g.a semiconductor circuit element, may include or be formed from aninsulated-gate bipolar transistor.

FIG. 18B illustrates a semiconductor device 1800 b according to variousembodiments in a method according to various embodiments in a schematiccross sectional view or side view, e.g. a semiconductor circuit element1702 a, 1702 b, 1702 c.

The semiconductor device 1800 b may include the doped collector region1081 formed on the second side 102 b. The doped collector region 1081may include or be formed from a first doping type. The doped collectorregion 1081 may include or be formed from a first junction region.

The semiconductor device 1800 b may further include a first contact pad1706 electrical contacting the doped collector region 1081. The firstcontact pad 1706 may include or be formed from an electrode contact pad.The first contact pad 1706 may include or be formed from a metallizationlayer.

Further, the semiconductor device 1800 b may include a first dopedregion 2006. The first doped region 2006 may include or be formed from asecond junction region. The first doped region 2006 may include a dopanthaving a doping type different from the doped collector region 1081 (inother words, the dopant of the doped collector region 1081), e.g. thesecond doping type. The semiconductor device 1800 b may further includea second contact pad 1708 electrical contacting the first doped region2006. The second contact pad 1708 may include or be formed from anelectrode contact pad. The second contact pad 1708 a may include or beformed from a metallization layer.

Optionally, the semiconductor device 1800 b may include a second dopedregion 2002 between the first doped region 2006 and the doped collectorregion 1081. The second doped region 2002 may include or be formed froma field stop region. The second doped region 2002 may include (e.g. adopant having) a doping type equal to the doped collector region 1081.The second doped region 2002 may include a dopant concentration higherthan the first doped region 2006.

The semiconductor device 1800 b, e.g. a semiconductor circuit element1702 b, 1702 b, 1702 b, e.g. a power semiconductor circuit element 1702,may include or be formed from a diode structure, e.g. a planar diodestructure (providing a vertical current flow). A diode structure mayinclude or be formed from one p-n junction, e.g. formed by an interfaceof two doped regions having different doping types, e.g. an interfacebetween the first doped region 2006 and the doped collector region 1081or an interface between the second doped region 2002 (if present) andthe first doped region 2006.

Optionally, the doped collector region 1081 may include or be formedfrom a plurality of first segments including the first doping type and aplurality of second segments including the second doping type. Thesegments of the plurality of first segments and the segments of theplurality of second segments may be disposed in an alternating order. Inthis case, the doped collector region 1081 may be part of backward-diodestructure.

The metallization layer may include or be formed from a powermetallization.

Further, various embodiments will be described in the following.

According to various embodiments, a semiconductor device may include: asemiconductor region; a metallization layer disposed over thesemiconductor region; and a self-organizing barrier layer disposedbetween the metallization layer and the semiconductor region, whereinthe self-organizing barrier layer may include or be formed from a firstmetal configured to be self-segregating from the metallization layer.

According to various embodiments, a semiconductor device may include: asemiconductor region; a metallization layer disposed over thesemiconductor region; and a self-organizing barrier layer disposedbetween the metallization layer and the semiconductor region, whereinthe self-organizing barrier layer may include or be formed from analloying element (e.g. a first metal) configured to be self-segregatingfrom the metallization layer.

According to various embodiments, the self-organizing barrier layer maybe in physical contact to at least one of the metallization layer or thesemiconductor region.

According to various embodiments, a temperature activating a segregationof the alloying element (e.g. the first metal) from the metallizationlayer may be less than a temperature activating a reaction of thesemiconductor region with the metallization layer.

According to various embodiments, a temperature activating a segregationof the alloying element (e.g. the first metal) from the metallizationlayer (also referred to as segregation temperature) may be less than180° C.

According to various embodiments, a concentration of the alloyingelement (e.g. the first metal) in the metallization layer may be in therange from about 0.5 at % to about 50 at %.

According to various embodiments, the self-organizing barrier layer maybe substantially formed from at least one of the alloying element (e.g.the first metal) or a compound including or formed from the alloyingelement (e.g. the first metal) and a semiconductor of the semiconductorregion.

According to various embodiments, a temperature activating a reaction ofthe semiconductor region with the alloying element (e.g. the firstmetal) may be greater than a temperature activating a reaction of thesemiconductor region with the metallization layer (e.g. with the hostmaterial of the metallization layer).

According to various embodiments, an electronegativity of the alloyingelement may be less than an electronegativity of at least one of thehost material or the semiconductor material

According to various embodiments, the alloying element (e.g. the firstmetal) may be at least one of manganese, tantalum, chromium, tungsten,molybdenum.

According to various embodiments, a thickness of the metallization layermay be greater than ten times a thickness of the self-organizing barrierlayer.

According to various embodiments, the metallization layer may include orbe formed from a self-segregating composition including the alloyingelement (e.g. the first metal).

According to various embodiments, a concentration (e.g. atomicconcentration) of the alloying element (e.g. the first metal) in themetallization layer may be less than at least one of a concentration ofthe host material (e.g. the second metal) in the metallization layer ora concentration of the alloying element (e.g. the first metal) in theself-organizing barrier layer.

According to various embodiments, the host material (e.g. the secondmetal) may be copper.

According to various embodiments, the metallization layer may besubstantially free of a semiconductor of the semiconductor region.

According to various embodiments, the semiconductor region may besubstantially free of a material of the metallization layer, e.g. atleast one of: the host material or the alloying element.

According to various embodiments, an interface of the self-organizingbarrier layer and the semiconductor region may be free of the hostmaterial (e.g. the second metal).

According to various embodiments, a specific resistance of at least oneof the metallization layer or the self-organizing barrier layer may beless than 70 μOhm·cm (micro-ohm centimeter).

According to various embodiments, a specific resistance between themetallization layer and the semiconductor region may be less than 70μOhm·cm.

According to various embodiments, a temperature stability of theself-organizing barrier layer is greater than a temperature activating areaction of the host material with the semiconductor region (e.g. thesemiconductor material), e.g. by more than about 10° C., e.g. by morethan about 20° C., e.g. by more than about 30° C., e.g. by more thanabout 40° C., e.g. by more than about 50° C.

According to various embodiments, a temperature activating a segregationof the alloying element from the metallization layer (e.g. the hostmaterial) may be less than a temperature activating a reaction of thehost material with the semiconductor region (e.g. the semiconductormaterial), e.g. by more than about 10° C., e.g. by more than about 20°C., e.g. by more than about 30° C., e.g. by more than about 40° C., e.g.by more than about 50° C.

According to various embodiments, the alloying element (e.g. the firstmetal) may be configured to segregate from the metallization layerfaster than the metallization layer chemically reacts with thesemiconductor region.

According to various embodiments, the metallization layer may include orbe formed from a power metallization.

According to various embodiments, the semiconductor device may furtherinclude: a contact pad formed at least one of in or over themetallization layer.

According to various embodiments, the metallization layer may include orbe formed from a first sublayer and a second sublayer, wherein the firstsublayer is disposed between the second sublayer and the self-organizingbarrier layer, wherein the first sublayer and the second sublayerinclude at least the host material and differ from each other in atleast one of a chemical composition, a thickness.

According to various embodiments, the first sublayer includes theself-segregating compound.

According to various embodiments, the semiconductor device may furtherinclude: an electronic power semiconductor element formed at least oneof in or over the semiconductor region, wherein the electronic powersemiconductor element is electrically coupled (e.g. electricallyconnected) with the metallization layer.

According to various embodiments, the semiconductor device may furtherinclude: at least one further barrier layer between the self-organizingbarrier layer and the semiconductor region, wherein the further barrierlayer may include one or more defects through which the self-organizingbarrier layer contacts the semiconductor region.

According to various embodiments, the semiconductor device may furtherinclude: at least one further barrier layer formed between theself-organizing barrier layer and the semiconductor region, wherein thefurther barrier layer may include or be formed from at least one oftitanium or tungsten.

According to various embodiments, a thickness of the self-organizingbarrier layer may be in the range from about 1 nm to about 20 nm.

According to various embodiments, a thickness of the metallization layermay be in the range from about 100 nm to about 1 μm.

According to various embodiments, a method may include: forming ametallization layer over a semiconductor region, wherein themetallization layer may include or be formed from a self-segregatingcomposition including a first metal and a second metal; activating asegregation of first metal from the self-segregating composition to forma self-organizing barrier layer between the second metal and thesemiconductor region.

According to various embodiments, a method may include: forming ametallization layer over a semiconductor region, wherein themetallization layer may include or be formed from a self-segregatingcomposition including an alloying element (e.g. the first metal) and ahost material (e.g. the second metal); activating a segregation of thealloying element (e.g. the first metal) from the self-segregatingcomposition to form a self-organizing barrier layer between the hostmaterial (e.g. the second metal) and the semiconductor region.

According to various embodiments, a concentration of the alloyingelement in the self-segregating composition is in the range from about0.5 at % to about 50 at %.

According to various embodiments, activating the segregation of thealloying element (e.g. the first metal) from the metallization layer mayinclude or be formed from heating the metallization layer, e.g. above asegregation temperature.

According to various embodiments, the method may further include:forming at least one further barrier layer between the metallizationlayer and the semiconductor region, wherein the further barrier layermay include or be formed from at least one of titanium or tungsten.

According to various embodiments, the self-organizing barrier layer isformed between the host material (e.g. the second metal) and at leastone further barrier layer.

According to various embodiments, a concentration of the alloyingelement (e.g. the first metal) in the metallization layer may be lessthan a concentration of the host material (e.g. the second metal) in themetallization layer, e.g. at least one of before or after the activatingthe segregation.

According to various embodiments, a method may include: forming ametallization layer over a barrier layer (e.g. the at least one furtherbarrier layer); wherein the metallization layer may include or be formedfrom a first metal configured to be self-segregating from themetallization layer; and healing a defect in the barrier layer bysegregating the first metal from the metallization layer at least one ofin or over the defect.

According to various embodiments, a method may include: forming ametallization layer over a barrier layer (e.g. the at least one furtherbarrier layer); wherein the metallization layer may include or be formedfrom an alloying element (e.g. the first metal) configured to beself-segregating from the metallization layer; and healing a defect inthe barrier layer by segregating the alloying element (e.g. the firstmetal) from the metallization layer at least one of in or over thedefect.

According to various embodiments, the alloying element may be inphysical contact with at least one of the metallization layer, thedefect, the barrier layer.

According to various embodiments, the alloying element may extend intothe defect.

According to various embodiments, the metallization layer may be heatedto a temperature greater than a segregation temperature of the alloyingelement (e.g. the first metal) in the metallization layer.

According to various embodiments, forming the self-organizing barriermay include or be formed from changing a chemical composition of themetallization layer.

According to various embodiments, a chemical composition of themetallization layer is changed by segregating the alloying element (e.g.the first metal) from at least one of the metallization layer orself-segregating composition.

According to various embodiments, a concentration of the alloyingelement (e.g. the first metal) in at least one of the metallizationlayer or the self-segregating composition may be reduced by segregatingthe alloying element (e.g. the first metal) from the metallizationlayer.

According to various embodiments, at least one of the self-segregatingcomposition, the host material, or the alloying element may beelectrically conductive.

According to various embodiments, the self-segregating composition mayinclude or be formed from a metal alloy, e.g. a self-segregating metalalloy, e.g. self-segregating binary metal alloy.

According to various embodiments, a chemical reactivity of the alloyingelement to the semiconductor material may be less than a chemicalreactivity of the host material to the semiconductor material.

According to various embodiments, a specific resistivity (e.g. aspecific bulk resistivity) of at least one of the host material, theself-segregating compound, or the alloying element may be less than aspecific resistivity (e.g. a specific bulk resistivity) of thesemiconductor material.

According to various embodiments, a specific resistivity (e.g. aspecific bulk resistivity) of at least one of the host material or thealloying element may be less than about 10 μOhm·m, e.g. less than about5 μOhm·m, e.g. less than about 2 μOhm·m.

While the invention has been particularly shown and described withreference to specific embodiments, it should be understood by thoseskilled in the art that various changes in form and detail may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims. The scope of the invention is thusindicated by the appended claims and all changes which come within themeaning and range of equivalency of the claims are therefore intended tobe embraced.

What is claimed is:
 1. A method, comprising: forming a metallizationlayer over a semiconductor region, wherein the metallization layercomprises a self-segregating composition comprising an alloying elementand a host material; and forming a self-organizing barrier layer betweenthe host material and the semiconductor region, wherein forming theself-organizing barrier layer comprises activating a segregation of thealloying element from the self-segregating composition forming a furtherbarrier layer between the metallization layer and the semiconductorregion, the further barrier layer comprising at least one defectincluding an opening extending through the further barrier, whereinforming the self-organizing barrier layer comprises sealing the at leastone defect in the further barrier layer with the self-organizing barrierlayer.
 2. The method of claim 1, wherein activating the segregation ofthe alloying element from the metallization layer comprises heating themetallization layer.
 3. The method of claim 2, wherein heating themetallization layer comprises heating the metallization layer to atemperature greater than a segregation temperature needed to activatethe segregation of the alloying element from the metallization layer. 4.The method of claim 1, wherein activating the segregation of thealloying element from the metallization layer comprises activating amigration of the alloying element from the metallization layer towardsthe semiconductor region.
 5. The method of claim 1, wherein activatingthe segregation of the alloying element from the metallization layercomprises reducing a concentration of the alloying element in themetallization layer.
 6. The method of claim 5, wherein the concentrationof the alloying element in the metallization layer before activating thesegregation is greater than the concentration of the alloying element inthe metallization layer after activating the segregation.
 7. The methodof claim 5, wherein the concentration of the alloying element in themetallization layer before or after activating the segregation is lessthan a concentration of the alloying element in the self-organizingbarrier layer.
 8. The method of claim 1, wherein a concentration of thealloying element in the metallization layer is less than a concentrationof the host material in the metallization layer.
 9. The method of claim1, wherein a concentration of the alloying element in the metallizationlayer is substantially homogenous in the metallization layer.
 10. Themethod of claim 1, wherein the metallization layer is in physicalcontact with the semiconductor region.
 11. The method of claim 1,wherein the self-organizing barrier layer comprises a barrier compoundincluding the alloying element and semiconductor material of thesemiconductor region.
 12. The method of claim 11, wherein aconcentration of the barrier compound in the self-organizing layerbarrier layer is greater than 70 at %.
 13. The method of claim 11,wherein a concentration of the barrier compound in the self-organizinglayer barrier layer is greater than 99 at %.
 14. The method of claim 1,wherein the alloying element includes at least one of manganese,tantalum, chromium, tungsten, and/or molybdenum.
 15. The method of claim1, wherein a thickness of the metallization layer before activating thesegregation is greater than a thickness of the metallization layer afteractivating the segregation.
 16. The method of claim 1, wherein athickness of the metallization layer before or after activating thesegregation is greater than one hundred times a thickness of theself-organizing barrier layer.
 17. The method of claim 1, wherein theself-organizing barrier layer physically separates the metallizationlayer from the semiconductor region.
 18. The method of claim 1, whereinthe alloying element is configured to segregate from the metallizationlayer faster than the metallization layer chemically reacts withsemiconductor material of the semiconductor region.
 19. A method,comprising: forming a metallization layer over a barrier layer; whereinthe metallization layer comprises an alloying element configured to beself-segregating from the metallization layer; healing a defect in thebarrier layer by segregating the alloying element from the metallizationlayer to at least one of in or over the defect.